The invention relates to active elements for use with magnetic heads and a method of manufacturing the elements, wherein the elements include nitrided magnetic members.
An important and continuing goal in the data storage industry is that of increasing the density of data stored on a medium. For tape storage systems, this goal has lead to decreasing track width in magnetic tapes, and increasing track density in magnetic tape heads. Similarly, for disk storage systems, this goal has lead to decreasing track width in magnetic disks, and increasing track density in magnetic disk heads. As track density in tape and disk heads increases, so does the need for precise processing and critical dimension control of recording elements and/or read elements disposed in the tape and disk heads.
Prior recording elements include magnetic poles that comprise nickel-iron alloys, such as permalloy, and are made using electroplating manufacturing methods. While electroplating provides good dimensional control, the resultant poles suffer from at least two problems. First, such poles have low resistivity values, and, thus, are not well suited for high frequency applications. Second, the poles are relatively soft, which results in increased pole tip recession.
More recently, poles have been made of alloys, such as cobalt-zirconium-tantalum, sputtered iron-nitride and sputtered nickel-iron-nitride, that are subjected to subtractive processing methods, such as wet chemical etching and electrochemical etching. These alloys, however, demonstrate different etching characteristics depending upon the material of underlying layers. Consequently, it is difficult to achieve precise dimensional control.
Prior read elements include a read structure sandwiched between top and bottom shields. The shields are made of a magnetic material such as ferrite, and the top shield is typically glued to the top of the read structure. With such a construction, it is difficult to achieve precise dimensional control.
Other prior read elements include shields made of nickel-iron alloys. While nickel-iron alloys provide good shielding properties, these materials wear excessively and, therefore, limit head life.
The invention overcomes the shortcomings of the prior art by providing improved active elements for use with magnetic heads and a method of manufacturing the active elements, wherein the active elements are hardened to increase wear resistance and/or resistivity.
Under the invention, a method of manufacturing an active element for use with a magnetic tape head includes depositing a magnetic material to form a magnetic member, and nitriding the magnetic member after the depositing step.
Preferably, depositing a magnetic material comprises depositing nickel-iron alloy. Furthermore, nitriding the magnetic member preferably includes plasma nitriding the magnetic member. Advantageously, plasma nitriding the magnetic member may be performed at a temperature below 300 degrees Celsius to avoid adverse effects on organic components of the active element.
Further under the invention, a method of manufacturing a recording element for use with a magnetic head includes depositing a seed layer proximate a substrate; electro-depositing a magnetic and electrically conductive material on the seed layer; and nitriding the material after the material has been deposited to increase at least one of hardness and resistivity.
More specifically, a method of manufacturing a magnetic head includes depositing a first seed layer proximate a substrate; electroplating a first layer of nickel-iron alloy on the first seed layer to form a first magnetic pole; plasma nitriding the first magnetic pole; depositing a gap material on the first magnetic pole; depositing a second seed layer on the gap material; electroplating a second layer of nickel-iron alloy on the second seed layer to form a second magnetic pole; and plasma nitriding the second magnetic pole.
According to a feature of the invention, plasma nitriding the first magnetic pole and plasma nitriding the second magnetic pole may be performed simultaneously. Alternatively, each pole may be plasma nitrided separately.
A method of manufacturing a read element according to the invention includes depositing a first seed layer proximate a substrate; electro-depositing a first layer of magnetic material on the first seed layer to form a first shield; nitriding the first shield; depositing a read structure on the first shield; depositing a second seed layer on the read structure; electro-depositing a second layer of magnetic material on the second seed layer to form a second shield; and nitriding the second shield.
Further under the invention, an active element for use with a magnetic head includes an electro-deposited magnetic member that is nitrided after electro-deposition to achieve at least one of a desired hardness and a desired resistivity. Preferably, the magnetic member comprises nickel-iron alloy.
These and other objects, features and advantages of the invention are readily apparent from the following detailed description of the best modes for carrying out the invention when taken in conjunction with the accompanying drawings.